Drum-actuated alarm.



E. AUFIERO.

DRUM AGTUATBD ALARM. Arrugnmn FILED JUNE 15, 1910.

WITNESSES: INVENTOR- fi i CmM W) :Patented Apr. 25,1911.

as PATENT OFFICE. x

EMANUEL AUFIERO, OF BROOKLYN, NEW YORK, ASSIGNOR TO AUTOMOBILE SUPPLY MFG. CO., BROOKLYN, NEW YORK, A CORPORATION OF NEW YORK.

DRUM-ACTUATED ALARM.

Specification of Letters Patent.

Application filed June 15, 1910.

Patented Apr. 25, 1911. Serial No. 566,997.

The object of my invention is 'to produce 3 an electro-mechanical alarm, thesound of which shall not be irritating and metallic.

Further object of my invention is to produce an alarm. emitting, at will, sounds of diiferent tones and penetrating power.

I attain these and other objects by the apparatus illustrated in the accompanying drawing, in which is shown a sectional view 1 of one embodiment of the entire alarm.

The frame. 3 has sleeve 4' into which sets disk 5 carrying the horn or sound projector 6. Between frame 3 and disk 5 is clamped a drum composed of ring 8 and two circular acoustic plates 9 and 9 secured to said ring: said drum is held between two soundproof washers 7 and.7'. Better acoustic re-,

sults are attained when plate 9 has near its periphery a number of holes exposing plate 9.

A. crown gear means of member 12' and nut 11. Frame 53 carries arm 13 supporting a small electric rotary motor 15, on the armature of which is secured a rotary member 14 carrying two cam projections 1 and 1 in operative engagement with crown gear 10. On sleeve 17 -1s secured a casing 16 which is used as resonj ator and to render the instrument dust-proof and Water-proof. It will be seen that, giving a rapid rotary motion to bar 14, acoustic plate 9 will receive a number of outward thrusts, which the surrounding air or me-- chanical means transmit to the other plate 9. 'With a crown gear 10 having a given number of teeth, sounds can be generated the pitch of which is directly proportional to the speed of the rotary member 14;. l

10 is fastened to plate 9 by- I have found that motor 15 can be of the variable-speed class, having preferably two speeds, one relatively low, the other high speed; so that connecting said motor with two push buttons commanding one or the other speed, sounds of low or high pitch can be at will generated. The natural frequency of one of the plates composing the drum can harmonize with thehigh speed of the motor;

the other plate can harmonize with the low speed. Better acoustic results are attained when ring 8 is madeof soft metal or soundproof material as fiber, hard rubber, etc.; the inner side .of'said ring is rounded as shown in .the drawing. The acoustic plates 9 and I 9 are made preferably of chrome steel or vanadium steel.

, It is understood that the vibrations of the drum are partly forced and partly free: the best resultsare attained when, in the return movement, the plates 9 and 9 are permitted full swing past their path of vibration before starting the next forced vibration. It is also understood that other variable speed means can be used to rotate member 1 1; and that plates 9 and 9', instead of steel, can be made of'any other suitable material.

Various changes in the form, arrangement and minor details of construction may be resorted to without departing from the spirit of said invention.

What I claim is:.

'In a signal or alarm device of the class described, a suitable casing'and sound projector, a plurality of acoustic plates, sound proof means separating the edges of said a disk having cam pro ections secured plates, to one of said acoustic plates, a rotary member engaging said cam projections, in combination with an electric rotary motor giving power to said rotary member, and giving therefrom vibrative energy to sald acoustic plates.

EMANUEL AUFIERO.

Witnesses ANGELO GUERRIERO,

WILLIAM P. MURPHY. 

